1. Technical Field
The disclosure generally relates to lens units and LED (light emitting diode) modules, and more particularly to a lens unit having a movable reflector, and an LED module incorporating the lens unit.
2. Description of Related Art
Nowadays LEDs (light emitting diodes) are applied widely in various applications for illumination. The LED is a highly pointed light source. Thus, light directly emitted from the LED may form a small light spot. However, the small light spot can only illuminate a small area. In order to achieve a large illumination area, a large number of LEDs are required to be incorporated together, thereby resulting in a high cost.
Therefore, a lens is used with the LED to modulate the light distribution of the LED. The lens can diverge the light emitted from the LED to thereby illuminate a large area. However, the light modulation capability of the lens is fixed once the lens is designed and manufactured. Thus, if different light distribution of the LED is required, the lens is required to be redesigned and manufactured, resulting in a high cost of illumination.
What is needed, therefore, is a lens unit and an LED module using the lens unit which can address the limitations described.